1. Field of the Invention
The present invention relates to a reinforcing bar binding machine in which a wire pulled out from a wire reel is fed to a guide part provided on the tip end of a binding machine body, curled by the guide part and fed out to the circumference of the reinforcing bars arranged inside the guide part, and looped and wound around the reinforcing bars and twisted to bind the reinforcing bars.
2. Background Art
A reinforcing bar binding wire is pulled out from the wire reel, and fed out from a guide part on the binding machine tip end while being curled, and looped and wound around reinforcing bars, and at the guide part, the wire must be curled and fed out. In order to curl the wire, the wire should be bent by at least three points.
That is, the guide part includes three components arranged in order, an end portion of a guide tube which guides feeding of the wire from the wire reel, a wire cutting mechanism for cutting the wire after feeding out a predetermined amount of the wire, and a curl guide which curves the wire fed from the wire cutting mechanism (refer to JP-B2-3496463). These three components have functions for cutting the wire and guiding the wire, and these are used as said three points for curling the wire.
However, the above-described configuration has the following problems.
The three components have complicated shapes, and easily vary in dimensions and attaching positions. Therefore, these may pose problems that the curl diameter of the wire fed out from the guide part is excessively small and the hooks cannot grasp the wire, or the curl diameter is excessively large and the end portion of the wire returned after being looped cannot enter a curl pickup guide of the guide part. Therefore, dimensional control is very troublesome and the component cost increases.
Further, the three components which curl the wire are always worn by the iron-made wire, so that they are worn, and in particular, a portion which forms a curl on the wire is greatly worn, and this wearing increases the wire feeding resistance and deteriorates the smoothness of the wire feeding, and during repetition of use, the curling is deteriorated, and the curl diameter of the wire becomes larger, so that for guiding the wire, the components need to be replaced. It is possible that the components are hardened to cope with the problem of wearing, however, the shapes of the components are complicated, so that selection of the material (hardness) is limited.
Further, for curling the wire, one point in said three points must be always disposed on the inner side of the wire (portion which becomes the inner side of the curl) without fail. When this portion is disposed on the tip of the wire cutting mechanism, wire cutting swarf may remain at the guide part. In this case, if the next binding operation is performed without knowing the swarf, the next wire jams at the guide part and it is troublesome to take this out.